Fuel control device for internalcombustion engines



J. A. GRANT July 3, 1951 FUEL CONTROL DEVICE FOR INTERNAL-COMBUSTION ENGINES 2 Sheets-Shea; 1

Filed Oct. 9, 1945 /vvewro e /a///v 6844 T J. A. GRANT 2,558,843

FUEL CONTROL DEVICE FOR INTERNAL-COMBUSTION ENGINES July 3, 1951 2 Sheets-Shed 2 Filed Oct. 9, 1945 Patented July 3, 1951 FUEL CONTROL DEVICE FOR INTERNAL- COMBUSTION ENGINES John Alexander Grant, New Westminster, British Columbia, Canada Application October 9, 1945, Serial No. 621,305

3 Claims.

This invention relates to a fuel control device for internal combustion engines which are subject to being driven by the load to which they are applied.

It frequently happens that when an automobile is travelling down hill its momentum is sufficient to cause the wheels of the vehicle to drive the engine instead of the engine driving the wheels and this condition becomes serious when, as usually happens, the accelerator pedal is released, the throttle butterfly valve returns to the idling position and a vacuum is created in the combustion chambers of the several cylinders of the engine.

As soon as the condition in which the wheels drive the engine has developed there is no further need for the admission of fuel to the combustion chambers and in view of this it would appear to be desirable to so adjust the throttle butterfly valve that when the accelerator is released the butterfly valve completely closes off the intake passageway to the intake manifold. Manufacturers have not done this, however, because of the extent of the vacuum which the pistons driven by the wheels of the automobile quickly create in the combustion chambers and in the manifolds. The result is that the manufacturers have provided a compromise which allows some air to travel past the butterfly valve in the idling position but at the same time permits the passage of fuel which is not required to drive the engine. Thus in the conventional automobile, gasoline is not only wasted but it drips down past the pistons and dilutes the oil in the crank case. The more serious disadvantages, however, arise from the fact that the vacuum formed in the combustion chambers draws oil up past the rings into the combustion chambers so that oil is burned, carbon is formed and spark plugs and valves are fouled.

In these circumstances various proposals have been made for automatically closing off the admission of fuel to the combustion chambers as soon as the wheels of an automobile start to drive the engine and at the same time by-passing air to the combustion chambers to relieve the vacuum which would otherwise be formed. The known devices of this type are, however, relatively complicated and expensive both in their original cost and in their upkeep so that they have not come into general use.

The object of the present invention is, therefore, to provide a relatively simple yet efficient device for automatically closing off the admission of fuel to the combustion chambers of an internal combustion engine of the type described and at the same time to admit air to such chambers.

A further object of the invention is to provide a device of this type which is electrically operated and in which the electric circuit therefor is only completed when both of two switches are closed, that is when the throttle valve is in the idling position but the engine speed has increased above idling speed.

Other objects and features of the invention will appear from the accompanying description with reference to the drawings in which Figure l is an elevation partly in section showing the control device in position below the throttle butterfly valve of an internal combustion engine,

Figure 2 is a plan view of the control device according to Figure 1,

Figure 3 is an end view of the installed device shown in Figure 1,

Figure 4 is a circuit diagram, showing the switches in the position which they occupy when the throttle is in the idling position and the engine is at idling speed,

Figure 5 is an elevation partly in section of the governor and governor switch; and

Figure 6 is a plan View of a modified form of air channel member for use with a dual-barrelled carburetor.

The control device consists essentially of an air channel member l0 connected between the intake manifold H and the carburetor unit I2, a butterfly valve l3 for closing oil the intake passageway M- of the unit I2, a solenoid I5 for actuating the valve l3, a valve [6 for controling the by-passing of air to the manifold ll through the air-channel member ID, and a solenoid H for actuating the valve I6.

The air channel member ID is connected between the respective flanges of the intake manifold and the carburetor unit l2 by bolts l8 and nuts I9 and it is formed with a passageway 2-) which is of the same diameter as and is aligned with the intake passageway 14 and is formed with a channel 2| which leads from the passageway 20 to a casing 22 connected to the channel member H! by means of flanges 23, bolts 24 and nuts 25.

The casing 22 which communicates with the 1 atmosphere through a dust cover 26, is provided at the lower end with a threat 21 which is closed by the valve member [6 connected to the armature 28 of the solenoid 11. When the solenoid is not actuated the armature drops by gravity thus allowing the valve member or plate l6 to engage a rim 29 forming a valve seating at the top end of the throat 21. When the solenoid is actuated the armature is drawn up thus lifting the valve member |6 from the seating 29 and allowing air to pass into the throat 21 and channel 2| to the passageway 20.

As will be seen from Figure 1 the armature is formed at the end with a shoulder 30 and a neck 3| and the connection between the valve member l6 and the neck 3| is such as to permit a slight movement of the valve member l6 longitudinally of the armature and to permit the passage of air between the neck 3| and the plate when the shoulder 30 has been lifted clear of the plate. The result is a double action arrangement in which initial movement of the armature when the solenoid is energized lifts the shoulder 30 clear of the plate l6 and permits sufficient air to pass between the neck 3| and plate l6 to break the vacuum in the throat 21. The relatively weak solenoid I1 is then suflicient to lift the plate l6 from the seating 29.

The solenoid coil 32 is spaced from the wall of the casing 32 by ribs 33 so that air is permitted to pass freely around the outside of the coil and to the throat 21. This particular arrangement is important because it provides for cooling of the coil by the air passing around it and results in heating the air which is by-passed to the engine so that its running temperature is maintained. The amount of air passing through the throat 21 may be adjusted in accordance with the manifold vacuum of the engine in question by turning the plug 34 up or down thereby altering the limit of travel of the armature 28 and at the same time adjusting the magnetic field of the solenoid in accordance with the requirements. The plug 34 is threaded into a cap 35 and its adjustment is held by a lock nut 36.

As appears from Figure 1 the shaft 31 on which the butterfly valve I3 is pivoted is journalled in the member In above the point at which the channel 2| meets the passageway 26. In the normal operation of the automobile the butterfly valve I3 is held in the open position shown in Figures 1 and 2 by the action of the spring 36 and it is moved to the closed position on energization of the solenoid l5, the armature 39 of which is connected by a link 40 to a crank lever 4| connected to the shaft 31. When the butterfly valve I3 is thus moved to the closed position the mixture of fuel and air which would normally pass to the intake manifold is prevented from doing so. When, as described below, the solenoid I1 is then energized, air is admitted to the manifold M through the cover 26, casing 22 and channel 2|, thus preventing a vacuum developing in the combustion chambers.

The two solenoids are grounded through the metal air channel member If] and they are energized through the respective leads 42 and 43, the lead 42 being connected to a switch 44 by means of which the solenoid I5 may be manually shorted out for test purposes. As appears from Figure 4 the leads 42 and 43 are then connected in series to a governor switch G and a throttle switch T illustrated respectively in Figures 5 and 1. Energy for the circuit is drawn from a battery B The switch G comprises two contact arms 43 and 46 each carrying a contact point 41 and mounted on a bracket 48 which carries a fly-balltype governor 49. A sleeve 50 is journalled in the bracket 48 and it carries a plate 5| provided with lugs 52 on which the fly ball arms 53 are pivoted. A cover 54 is connected to the plate 5| and is provided with a. shallow groove for engagement as a pulley by the conventional fan belt of an automobile.

The arm 46 is a leaf spring and it is provided with an extension which carries an insulating disc 55 norm-ally engaged by the end of shaft 56 which extends through the sleeve 50 and is urged to the right in Figure 5 by spring 51 to hold the contact points 41 separated. As the speed at which the cover 54 is driven increases, the ball 58 of each fly ball arm 53 moves outwardly in known manner thereby moving the end 59 of each such arm to the left in Figure 5 so that each such end engages a head 60 connected to the shaft 56 and moves the shaft 56 to the left against the action of spring 51 thereby allowing the contacts 41 to close. The spring 51 abuts against the shoulder 6| and its compression is adjusted by the nut 62 in order to vary the speed at which the arms 53 overcome the spring and move the shaft 56 thereby allowing the contacts 41 to close. The speed at which the governor operates to clos the contacts 41 is above the idling speed of the engine.

Because switches G and T are in series neither solenoid will be actuated unless the switch T is also closed. This consists of a fixed contact 63 and a moveable contact 64 carried by a leaf spring 65. As shown in Figure 1 the lever 66 which is actuated from the accelerator control by a rod or cable 61 and is connected to operate the throttle butterfly valve 68 is provided with an extension 69 extending therefrom at an angle. When the throttle is in the idling position the extension 69 engages an insulating disc 10 connected to the top surface of the leaf and forces the leaf down until the contact 64 engages the contact 63. As soon as the throttle is moved from the idling position the contacts 63 and 64 are allowed to separate.

The two solenoids, one closing the butterfly valve I3 and the other opening the plate valve l6, are thus actuated simultaneously whenever the two switches G and T are both closed. The switch T is closed whenever the throttle butterfly valve is in the idling position and the switch G is closed whenever the engine exceeds the idling speed and therefore drives the pulley 54 fast enough to move the shaft 56 to the left and allows the contacts 41 to close. The switch G is thus closed during the normal running of the automobile but the switch T is only closed when the throttle is in the idling position so that both are closed only when the wheels of the automobile are driving the engine at more than idling speed.

What I claim as my invention is:

1. A fuel control device for internal combustion engines subject to being driven by a load, comprising in connection with the intake passage from the carburetor to the manifold a valve operable to close the intake passage, spring means adapted normally to hold said valve in the open position, a solenoid adapted to close said valve, a passage adapted to by-pass air to said intake passage on the manifold side of said valve, a valve closed only when the engine is actually running above said predetermined speed.

2. A fuel control device for internal combustion engines subject to being driven by a load, comprising in connection with the intake passage from the carburetor to the manifold a valve operable to close the intake passage, spring means adapted normally to hold said valve in the open position, a solenoid adapted to close said valve, a passage adapted to by-pass air to said intake passage on the manifold side of said valve, a valve, means for heating the air in the air passaid last-mentioned valve normally being closed, a solenoid adapted to open the last mentioned valves, means for heating the air in the air passage, and a circuit for energizing said solenoids comprising two switches connected in series, one switch being closed only when the throttle is positioned for operation of the engine below a predetermined speed and the other switch being closed only when the engine is actually running above said predetermined speed.

3. A fuel control device for internal combustion engines subject to being driven by a load, comprising in connection with the intake passage from the carburetor to the manifold a valve operable to close the intake passage, spring means adapted normally to hold said valve in the open position, a solenoid adapted to close said valve, a passage adapted to by-pass air to said intake REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 109,476 West Nov. 22, 1870 1,077,503 Anderson Nov. 4, 1913 1,813,719 White July '7, 1931 1,887,515 Pulkinghorn Nov. 15, 1932 1,970,002 Ericsson Aug. 14, 1934 2,022,094 Shoemaker Nov. 26, 1935 FOREIGN PATENTS Number Country Date 261,022 Great Britain ..Oct. 13, 1927 

